Interruption of schistosomiasis transmission in mountainous and hilly regions with an integrated strategy: a longitudinal case study in Sichuan, China

Abstract

BackgroundSchistosomiasis remains a major public health concern in China. Since 2004, an integrated strategy was developed to control the transmission of Schistosoma japonicum in China. However, the long-term effectiveness of this integrated strategy for the interruption of schistosomiasis transmission remains unknown in the mountainous and hilly regions of China until now. This longitudinal study aims to evaluate the effectiveness of the integrated strategy on transmission interruption of schistosomiasis in Sichuan Province from 2005 through 2014.MethodsThe data regarding replacement of bovines with machines, improved sanitation, access to clean water, construction of public toilets and household latrines, snail control, chemotherapy, and health education were captured from the annual report of the schistosomiasis control programmes in Sichuan Province from 2005 to 2014, and S. japonicum infection in humans, bovines and snails were estimated to evaluate the effectiveness of the integrated strategy.ResultsDuring the 10-year period from 2005 through 2014, a total of 536 568 machines were used to replace bovines, and 3 284 333 household lavatories and 15 523 public latrines were built. Tap water was supplied to 19 116 344 residents living in the endemic villages. A total of 230 098 hm2 snail habitats were given molluscicide treatment, and 357 233 hm2 snail habitats received environmental improvements. There were 7 268 138 humans and 840 845 bovines given praziquantel chemotherapy. During the 10-year study period, information, education and communication (IEC) materials were provided to village officers, teachers and schoolchildren. The 10-year implementation of the integrated strategy resulted in a great reduction in S. japonicum infection in humans, bovines and snails. Since 2007, no acute infection was detected, and no schistosomiasis cases or infected bovines were identified since 2012. In addition, the snail habitats reduced by 62.39% in 2014 as compared to that in 2005, and no S. japonicum infection was identified in snails since 2007. By 2014, 88.9% of the endemic counties achieved the transmission interruption of schistosomiasis and transmission control of schistosmiasis was achieved in the whole province in 2008.ConclusionThe government-directed and multi-department integrated strategy is effective for interrupting the transmission of schistosomiasis in the mountainous and hilly regions of China.

Knowledge, attitudes and practices related to schistosomiasis transmission and control in Leyte, Philippines

“…In 2004, China implemented an integrated strategy for schistosomiasis control that includes mass treatment and education but also snail control, improved sanitation, and replacement of working bovines with agricultural machinery [16, 17]. This shift has resulted in the elimination of human schistosomiasis cases in formerly endemic communities, as well as the elimination of infected bovines and snails in selected areas [16, 17]. However, it is important to note that most rural endemic communities such as Macanip suffer from long-term poverty as well as disease.…”

Effectiveness of the new integrated strategy to control the transmission of Schistosoma japonicum in China: a systematic review and meta-analysis

“…It is therefore assumed that the successful intervention packages piloted in the marshland and lake regions are not fully suitable for the hilly and mountainous environments in the Sichuan and Yunnan provinces of China [ 36 ]. Although field studies have shown that this new integrated strategy remains effective to control S. japonicum infection in humans and snails in hilly and mountainous endemic foci [ 26 , 27 , 57 ], regionally flexible integrated, intersectoral, and setting-specific control strategies driven by local circumstances and data are needed [ 36 ].…”

“…The morbidity control strategy, also known as the conventional strategy, focuses on synchronous chemotherapy for humans and bovines [ 4 ], and the new strategy developed in 2004 intervenes in the transmission pathway of schistosomiasis japonica, mainly including replacement of bovines with machines, prohibition of grazing cattle in the grasslands, improving sanitation, installation of fecal-matter containers on boats, praziquantel drug therapy, snail control, and health education [ 42 ]. This new integrated control strategy has proven to be highly effective to reducing the rate of S. japonicum infection in both humans and the intermediate host snails [ 24 , 26 , 39 , 43 , 46 , 65 , 66 ]. However, the effectiveness of this new integrated strategy varies in previous reports in terms of the implementation in different endemic regions and different local circumstances [ 36 ].…”

Elimination of schistosomiasis: the tools required

“…Although of less severity then the Yangtze River Basin with respect to schistosomiasis endemicity, the mountainous areas in eastern China are a major problem since the topography impedes large-scale approaches requiring somewhat different strategies than those used elsewhere. Liu et al [ 16 ] report good results from a 10-year longitudinal study evaluating a small-scale approach where an important ingredient is the replacement of bovines with machines. Chemotherapy, snail control and sanitation were also used and information, education and communication (IEC) materials were distributed to each household.…”